The present invention relates generally to assembly processes, and more particularly, to mechanical HVAC control head systems.
Vehicle assembly plants often produce several hundred vehicles per day. This type of production demand places a significant burden on the plant assembly operators who must construct these vehicles. Not only must the assembly operators correctly assemble various types of component configurations, but they must also meet daily production goals. To maintain a competitive position, vehicle manufacturers strive to create innovations that reduce cost while maintaining quality. One such innovation is to reduce overall vehicle assembly time.
The installation of heating, ventilation and air-conditioning (HVAC) systems into vehicles inherently poses assembly problems. Assembly problems arise with HVAC systems because the user interface mechanisms, such as knobs or switches, typically are coupled individually to the system they control. These individual coupling requirements significantly slow vehicle assembly time and increase overhead costs.
An increasingly common approach to reduce overall vehicle assembly time is to require component manufacturers to pre-assemble as much of the components as possible. The pre-assembled components are then shipped to the vehicle assembly plant for installation in a vehicle. Because the assembly operators"" time is not occupied as much by pre-assembly needs, the overall amount of time spent assembling the vehicle is reduced. This reduction in time directly impacts costs by reducing overhead and increasing the rate of production.
In HVAC systems where the user interfaces are mechanical, as when knobs are used, HVAC component manufacturers couple knobs to a faceplate, such as by use of push tabs, and deliver the sub-assembly to the vehicle assembly plant. During assembly, the assembly operators have to snap fit or otherwise affix the faceplate to the vehicle instead of coupling the knobs individually to the faceplate. To complete the HVAC system assembly, the assembly operator needs to make the connections between the function interfaces, such as rotary cylinders, and the knobs.
The difficulty with assembling the HVAC system in the manner described above is that once installation is complete, the assembly operators do not know if the function interfaces are properly aligned, installed and operational. The assembly operators can verify the installation only by activating the entire HVAC system. The time the assembly operators take to activate the entire HVAC system slows overall vehicle assembly time.
These disadvantages the assembly operators encounter when installing HVAC systems have made it apparent that a new technique to install the user and function interfaces is needed. This new technique should adequately couple the function interfaces to the user interfaces in one step. The new technique also should also eliminate the need for the assembly operators to verify installation by activating the entire HVAC system. The present invention is directed to meeting these ends.
One object of the invention is to provide an improved and reliable means to install a mechanical control head system into a vehicle. Another object of the invention is to decrease the number of steps necessary to install the mechanical control head system. A third object of the invention is to improve the diagnostic capability of the overall HVAC system.
In one aspect of the invention, a vehicle has a mechanical control head system that controls certain HVAC functions. The mechanical control head system includes a mounting plate, a faceplate, at least two mechanical, user-adjustable actuators, such as knobs, and at least two function interfaces, such as rotary cylinders. If the mounting plate is integrated into the HVAC module, the mechanical control head system is coupled to the HVAC module and then the HVAC module is attached to the vehicle. If the mounting plate is not integrated into the HVAC module, the individual components of the mechanical control head must first be coupled to the mounting plate and then the mounting plate is attached to the HVAC module. The mounting plate can be attached to the vehicle in a variety of ways, such as by fastening the flanges on the mounting plate to the vehicle instrument panel using screws, bolts or other conventional fasteners. Next, at least two rotary cylinders are coupled to the mounting plate by sliding them into pre-cut, floating slots on the mounting plate. Then at least two knobs are coupled to the faceplate. The knobs allow the user a means to control, for example, the ambient temperature in the vehicle interior, whether outside air circulates in the vehicle, etc. In accordance with the present invention, the knobs are coupled to the rotary cylinders in a single step instead of requiring individual steps for each knob. Likewise, the knobs can be decoupled from the rotary cylinders in a single step. Finally the faceplate is coupled to the mounting plate. Because the knobs can be installed in one step, the assembly operator no longer has to activate the entire HVAC system to verify correct installation, which reduces the overall amount of time spent assembling the vehicle. Instead, the component manufacturer tests the HVAC module for correct operation before it is shipped to the vehicle assembly plant.
The present invention thus achieves an improved mechanical control head system for a vehicle. The present invention is advantageous because it reduces the number of steps required to install and uninstall the system. Additionally, the present invention reduces the length of rotary cylinder cable needed because of the simplified installation process. Finally, the present invention allows for a simplified diagnostics process to be performed on a malfunctioning HVAC module.